Method of condensing ammonia.



L.VBL00K. METHOD OP CONDBNSING AMMONIA. APPLIUATION FILED JULY 24, 1,911.

Patented Mar. 18, R913.

WITNESSES: y@

INVENTOR im@ g) ATTORNEY LOUIS BLOCK, OF MAMRONECK, NEW YORK.

METHGD 0F CGNDENSING AMMONIA.

noaaiaa.

Speciceton of Letters Patent.

Application lelA July 24, 1911. Serial No. 640,161.

To all whom it may concern.' Be. it known that I, Louis BLooii, a citizen of the United States, residing at Mamaroneck, in thefcounty of Westchester and at which it is received in this art, at a high temperature and at a pressure of say twelve atmospheres. Y

I employ coils in the ordinary form, sometimes called trombone I cool these coils by a descending current ,of cold water on its exterior. I introduce the gas at the bottom, and retain the condensed gas mingled with the uncondensed in a gradually diminished ratio as both together move rapidly7 upward.

There is an economical means of transferring heat known as counter-current heatexchanging my method involves this. There is an advantage in ultimately receiving the condensed ammonia for refrigerating and most other uses in the arts not only liquid but also cold. My method involves this. Heat is transferred more rapidly across between liquids than between gases and liquids. My method involves this. My

method attains the heat. eirchan ing-'and thus cools the gas with less pipe sur ace by reason of the hot gas entering at the bottom, giving up its superheat to the lowest pipes which the cooling -water is just about to leave, and all the way up the rapidly cooling gas finds itself more and more cool by being under the influence of cooling water always only a little cooler-. My method delivers the 'condensed ammonia colder than usual by reason of its leaving the upper pipe which is bathed in the .latest-received water. And my method attains the more rapid transfer of heat by reason of using the condensed ammonia as an internal condensing agent and conveying the heat by such medium to the iron and then to the cold water.

In the working of my invention the ammonia enters the'coil in the form of hot gas at the bottom. In rising, it parts first with its superheat and afterward with the latent heat which has before maintained its vaporous condition, which we may continue to call gaseous. If the hot gas enters the .Patented Mar. I8, i913.

lowest pipe in any condensers now used in the art it is for the purpose of removing the superheat. It is in such condensers next transferred to the upper pipe of the coil and travels downward and the liquefied gas is discharged near the bottom. In some modifica-tions the Vgas enters the lowest pipe and is caused to travel upward. In such however the pipes have been provided ,with liquid drains so-that the liquid which forms by condensation is drained oft1 as soon as it forms and the gasascends dry.

I have discovered that it is practicable to cause the gaseous ammonia, and the' liquid ammonia whichis produced by its condensation to mix together, and to have the mixture move rapidly upward in the whole of the s ace, the proportion of the dense liquid being small at fthe bottom, and growing llarger as the niiirture rises, until all is liquid,'-all is condensed ammonia, and is carried away as such from the' top of the coil, cooled at `last to a low degree. My method of operating utilizes this discovery. The invention gives an immense increase to the area of the condensing surface in a form which is distributed throughout the whole volume of the interiors of the pipes, by using the liquid ammonia to condense.y succeeding instalments of gaseous ammonia. The gas rises in globules, or bubbles, constant-ly growing smaller. The previously condensed ammonia in its form of a dense liquid ills the spaces and applies against the whole exterior of every globule of the gas, and against the whole inner surface of the metal of the pipes and of the returns. The previously condensed ammonia serves as an agent between the bubbles of gas and the inner surfaces of the-metal. The act of condensation is proceeding over the Whole of the immense surface presented by these'small globules of gas. The heat moves outward rapidly from the bubbles into the dense liquid. The liquid in its turn circulates actively against the whole inner surface of the metal, and the heat moves outward rapidly from the liquid into the metal. The eXteriors of the metal parts are cooled by the descending water, the coldest water striking on the coldest pipe, then on the next pipe below which is slightly warmer, and so on, giving the advantages of the long known counter` current heat exchanging.

I will be as specific as I am able with present informatlon in regard to the increased activity ot the transfer of heat by my method. Birperiments in the arts have established that water or other similar liquids under similar conditions absorb heat from other water or liquid through metal (or when oppositely conditioned, impart heat to other liquids through metal) tive times as last as gaseous ammonia. With water to water the transfer of heat through iron or steel is 300 B. T. ll. per hour while with gas to water as in ammonia condensers now in use the transfer is only 60 B. T. ll. per hour tor each square foot oit surface and each degree of Bah. dililerence of temperature. 1We cannot know all the action under di'erent conditions, but it is largely dependent upon how tast" the heat ot the liquid ammonia can be transferred through the iron pipes to the water flowing over them. The transiter of heat from the interior ot the ammonia bubbles to the liquid ammonia surrounding them, and the transfer ot heat frourthe dense liquid to the metal inclosing it andthence to the water outside, is probably about at the rate of 300 B. T. U. per hour. The two transfers of heat in my method are each made at a rate occupying only one"r filth of the time which is required by the old method for its single transfer. Thus reclroned mathematically the efhciency of my method is greater than the ordinary in the ratio ot 5 to l. lt is not important that these ligures be exactly correct, l give them as the nearest now available.

The following is a description ot what l consider the best means of carrying out the invention on a moderately large scale.

The accompanying drawings form a part of this specication.

` Figure l is a perspective view ot the main portion ot the apparatus employed, and Fig. 2 is a side elevation ot the same, with water-supply properly added. llig. 3 is a side elevation of a portion, and F ig. 4t shows another mcdihcation in side elevation with dotted lines an internal pipe perforated to introduce the gas.

Similar letters and marks ot reference indicate corresponding parts in all the hgures.

I show iron pipes, preferably galvanized pipes, connected together as usual, in sections with returns. T show four sections each sixteen pipes high to obtain suiliciently extended condensing surfaces l introduce the hot gaseous ammonia at the bottom ot each section and cause it to move rapidly upf ward therein and totlow away steadily at the top in the :torni of dense liquid.

Referring to the letters of reference on the illustrative drawings, A ll, etc., are horizontal iron pipes and il are return bends or couplings by which each tier is united into what is sometimes termed a trombone coil. Ils shown these coils are mounted side by side. ln these the condensing oil the gaseous ammonia and also the preliminary cooling oft it, and the subsequent further cooling of the liqueiied ammonia is ed'ected.

y B is a horizontal pipe which receives the gaseous ammonia through a vertical pipe B* and an intermediate check valve and distributes it to the several coils through the means of descending pipes B B,`etc., controlled by coclrs or valves B2, and joined to the trombone coils with proper care lto maintain tight joints as will be understood.

D is a. pipe which takes away' the condensed ammonia, receiving it through the branches D extending up and down, and making proper-tight connections with the uppermost pipe in each of the coils. lt is essential that these branch pipes D and the header pipe B should have sufficient internal area to carry away the liquefied ammonia as it reaches the top ot the coil. Roughly each pipe D must beef sullicient size to carry away 200 gallons .of liquefied ammonia per hour from the condenser to the liquid receiver not shown.v The latter is located in the engine roomy while the condensers are placed upon the tloor above and since the top of the liquid receiver is equalized with the top ot the condensers, the hydraulic pressure under which the liquefied ammonia is forced through the condensers is that which is due to the static head plus the pressure due to the momentum of the inrushing gas less the triction head.

B2 are stop valves or cocks in the pipes D There is`a separate trough for condensing water over each of these coils with a separate supply pipe for each, as indicated in lig. 2, where M is the supply pipe and N the trough tor each. The gaseous ammonia tlows inward continuously past the check valve into the pipe B and down through the several pipes B into thevbase of each coil. lt dows through the condensers by moving alternately to the right and left through the several straight pipes A. and upward through thefseveral returns A till it reaches the top, becoming condensed and also `cooled. in the passage in the manner explained above by giving its heat ultimately to the shower otcold water descending outside trcm pipe to pipe. The condensed ammonia descends through the branch delivery pipes B into the general delivery pipe D and is led away by the latter.

There is a liability to difference ot pres sure in the several coils. This is avoided by providing an equalizing header or pipe E, which communicates by a vert-ical extension downward with the liquid header l) and also communicates independently with the several coils by branches B controlled by cocks or valves lt is sometimes desired to allow the gas to flow backward from the pipe B past the check valve; to attain this l provide a bypass pipe B3 controlled by a cock or valve B4.

lt is sometimes required to drain the ammonia entirely from the coils. To attain this l provide the connections D3, one for each, connecting low points in the coils with the drain header BS, each controlled by a cock or valve D4. During the operation of the condensers these valves D4 are kept tightly closed.

It is sometimes desired to enlarge or contract the capacity of the condenser. I provide joints which allow` this, and also facilitate themanufacture and transportation.

D5 is a cock or valve at the point shown in the discharge pipe D which can be Opened to facilitate drainage at intervals -if required. rllhis is ordinarily kept closed, and the pipe D discharges not directly but by the liquid ammonia ascending in the pipe Eik, which serves for this purpose in addition toits duty in connection with the equal izing pipe E and at a convenient height on this pipe, a. connecting pipe D D7 extends along over the line of the discharge, and makes an independent union With the latter. rlhis construction serves as a trap or liquid seal, and prevents the discharge of unliquetied gas from the condenser under any conditions.

Operation: The gaseous ammonia introf duced at the bottom in rising in the condenser changes its condition by condensation to that of a dense liquid. The liquid is retained and tends by its gravity to descend, but such descentI is opposed by the strongly ascending current of gaseous ammonia and there is active agitation. The result is an intimate mingling of the gas received at the bottom with the liquid in various degrees of coldness occupying the interior of the pipes, and tinally the liquid alone to which all becomes reduced flows away cold from the top.

'ils compared with the ordinary methods of operating, there is a greatly increased condensing surface by my method. The whole exteriors of all the globules of gas throughout every portion of Athe interior space in the coil is lying in contact with and completely surrounded by a bath of cooler liquefied ammonia. -All thatl great area is condensing surface and is ample to effect the 2 condensation, and the entire interiors of all the pipes and the returns is available with the increased emciency of live to one as cour pared to the ordinary method, for the transt'cr of the heat to the metal and thence to the cooling nater.

rThe ammonia vapor or`gas which enters the lowest pipe of each coil in a strong current and at a high velocity will interniingle echanically with the liquid contained e rninture will thus forced rapidly upward. The cold Water should be supplied in such quantities according to the temperature that the gas will all be condensed several pipes below lthe top.` The dense liquid alone will then travel upward through the upper pipes of each coil and being there subjected to the cooling action of the coldest water will itself be cooled to the lowest practicable degree, which is especially valuable in refrigeration.

Modifications may be made Without departing from, the principle or sacrificing the advantages of the invention. A greater or less number of coils may be associated in one condenser and a greaterV or less Anumber of pipes may be joined in each. lAll maybe of uniform diameter or the loWerm'ost which convey the current of gas before it has been reduced in volume may with advantage be much the largest.

Fig. 3 shows a provision for introducing a part of the hot gaseous fluid a little above the bottom of the coils. 'This may be found expedient under some conditions as when the pipes of the coils are of-uniform size and the gas is appreciably throttled in being compelled to pass its whole volume through the lower pipes.

Fig. 4 shows provisions for introducing' the gas into a large bottom pipe which insures its agitation atthat early stage. l esteem it-a desirable form of those parts.

'l claim as my invention:V

l. In condensing gaseous ammonia under pressure, rendering available the capacity of liquids to receive 'and impart heat more rapidly than gas, byreceiving the gas at a sucient velocity to overc-rm much resistance by its momentum, retaining the liquid which is produced by the liquefaction in one part of the condenser, and leading it with the uncondensed gas indirectly by an upward incline into another part mingled together and agitated, so that the liquid serves to condense the gas byk reason of the u great area and the nature of the contact surfaces and to be itself kept cool. by actively circulating in contact with the inclosing casing.

2. The method of condensing ammonia `gas under pressure which consists in equalizing its gaseous pressure by means of an independent passage, mixing it with liqueill lied ammonia previously in place, trapping v itl to resist accidental motions, leading it indirectly upward impelled by the velocity by which the gas is received and cooling the whole eiiternally.

.5. 'ifhe method of condensing ammonia V' sion at all points, mining it with ai'ninonia, conveying it indirectly up- .ring away the heat by Water the. outer pressure consisting in equaliaing Ll. 'llhe method ot condensingl ammonia gas which consists mining it with previously liqueilied ammonia under pressure, taking away the heat through metal wetted on one Side hy water and on the other side by agitation ot 'the mingled gaseous andrliquetied ammonia, leading it indirectly upward impelled by momentum, retaining and using it as a condensing medium tor further .instalments, leading1 it avvay completely condensed and .carrying it high so that the liquid is trapped against liability to he accidentally moved.

5. rthe method of liquetying' gases consisting oi discharging `the gas into liquefied gas lying in tiers one ahove another partly separated and partly connected together, with the gas pressure edualized, subjected to an external cooling action during' the operation, and causing the newly introduced gas to mingle with the liqueiied ammonia and both to circulate intimately and to travel indirectly upward together' until all the gas is liqueiied.,

t3. 'lhe method ot liquetying gases consisting ot discharging the gas into a series ot divided layers ot gas the uppermost ot which are/entirely and the lowermostare partially condensed vvhile activeliquetaction is going?,r on, causing the newly-inducted gas to intermingle with the liquefied gas and with the previously received gas, and allto travel forward and indirectly upward together and subjecting the globules ot the uncondensed gas to the cooling action ot the liqueiied gas surrminding,J them while the Whole is cooled hy means oit Water 01' other cooling7 medium moving in a thermally diverse direction, ideally discharging' the whole in a 'completely liuuetied condition at the top.

T. The method et liduetying gases consisting? ot discharging-the gas into a low point in a coil in tv 'ch the upper pipes are entirely and the lowerznipes partially filled with liquefied withoiit draining the coil, and while suloie ting the contents to a cooling action externally, and iinally discharging the ammonia cole at the too.'

8. ln condensing gas under pressure rendering available the facility ot receiving' and imparting heat possessed by liquids and also promoting etliciency and economy hy retaininel the condensed gas mingled and agitated, allowing a free movement thereof, in a thermally diverse direction trom that ot the cooling' medium, and with the pressure of the gas equalized, then trappingq against accidental iioW--by carrying it to a high level.

9. ln condensing'gas under pressure lead ing the .gas gradually upward ,through a suitable container and permitting a flow ot cooling Water downward over the container, retaining the liquid which is produced by the condensation at lovv points, mingling it with the uncondensed gas at higher points, receiving the gas at a sutlicient velocity to overcome hy its momentum the `gravity ot' the liquid produced and carrying the mixture indirectly upward until all is condensed, and further, so as to deliver the condensed gas cold.

l0, The method of condensing ammonia gas comprising the leadingit rapidly but indirectly upward overheat conducting' sur- -laces which are lrept'cooler, continuing; the .ascent until it is condensed, and causing the reduction of velocity to overcome by momentum the resistance of gravity as it changes to the denser form.

l1. The method described of presenting' gaseous ammonia with velocity and indirect ascending motion to heat conductingl surfaces in a container, causing it to reduce its velocity so that its momentum will urge it forward, presenting a cooling agent, as a shower of Water, to contact with the other tace ot the container, continuingl the cooling action on-the ascending; ammonia after it is ally condensed and taking away the liquid ammonia cold.

Signed at New York city in the county ot New York and State of `lie'vv York this 20th day o't July A. D. 1911.

LUlS BLCK. lvVitnesses Louis BLOCK, elr., lloUis ihr Coinin-- 

